Fault Diagnosing of Cycloidal Gear Reducer Using Statistical Features of Vibration Signal and Multifractal Spectra

Abstract

The article presents a method for diagnosing cycloidal gear damage on a laboratory stand. The damage was simulated by removing the sliding sleeves from two adjacent external pins of the cycloidal gearbox. Damage to the sliding sleeves may occur under operating conditions and can lead to the destruction of the gear unit. Hence, early detection is essential. Signals from torque sensors, rotational speed sensors and vibration acceleration sensors of input and output shafts for various rotational speeds and transmission loads were recorded. The frequency analysis of these signals was carried out. Due to the fluctuation of the rotational speed, the frequency spectrum gives an approximate picture and is not useful in detecting this type of damage. The statistical characteristics of the signal were determined. However, only statistical moments of higher orders, such as kurtosis, are sensitive to the tested damage. Therefore, the use of multifractal analysis of the vibration signal using the wavelet leader method (WLMF) was considered. Then log-cumulants of the multifractal spectrum were selected as the new signal features.

An Analysis of Power Friction Losses in Gear Engagement with Intermediate Rolling Elements and a Free Cage

“…Taking into account the proportional dependence of the radii of the generating circles of links, let us substitute expressions for gear ratios in the following dependence (11):…”

“…Many works are devoted to the study of the engagement of cycloid gears [2][3][4][5][6][7][8]. But pin gears, in which there are no intermediate rolling elements, are mainly studied [9][10][11][12][13][14][15][16][17][18]. In [9], the efficiency coefficient in the engagement of a pin gear with pins without bushings and with bushings was investigated.…”

“…In another work [10], authors developed a nonlinear dynamic model of a needle bearing, taking into account the friction among a cycloid wheel, a needle roller and a bearing cage in a pin gear. The study [11] presented a method for diagnosing damage to a cycloid tooth wheel of pin toothing on a laboratory bench based on a frequency analysis of vibration signals. In [12], the distribution of forces in pin toothing was considered, taking into account the finger deflections of a pin wheel; an improved model of the load distribution of an uncoordinated kinematic cycloidfinger pair was proposed.…”

Modification and Optimization of Cycloidal Gear Tooth Profile Based on Machining Error Compensation

“…The cycloidal gear mathematical model can facilitate the quantitative analysis of the cycloidal gear. The standard cycloidal gear profile equation is given as follows [13]:…”

“…Li et al [12] proposed an improved load distribution model of the mismatched cycloid-pin gear pair with ring pin position deviations and demonstrated the influences of ring pin position deviations on the distributed load, contact stress, loaded transmission error, and instantaneous gear ratio of the mismatched cycloid-pin gear pair. Komorska and Grosso studied the diagnosis of problems in the cycloidal gears and cycloidal gearboxes, respectively [13,14]. Additionally, many scholars have also conducted research on cycloidal gearboxes [15][16][17][18][19].…”